Light for use in activating light-activated materials, the light having insulators and an air jacket

ABSTRACT

Light system useful for activating light-activated materials are disclosed. Various configurations of light emitting semiconductor chips and heat sinks are disclosed, as well as various structures and methods for driving, controlling and using them, and materials and structures usable therewith.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation-in-part of

U.S. patent application Ser. No. 10/067,692 filed on Feb. 4, 2002 nowU.S. Pat. No. 6,755,648;

U.S. patent application Ser. No. 10/072,850 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,988,891;

U.S. patent application Ser. No. 10/072,659 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,981,867;

U.S. patent application Ser. No. 10/072,853 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,755,648;

U.S. patent application Ser. No. 10/072,859 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,755,649;

U.S. patent application Ser. No. 10/072,613 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,974,319;

U.S. patent application Ser. No. 10/072,302 filed on Feb. 5, 2002;

U.S. patent application Ser. No. 10/072,635 filed on Feb. 5, 2002;

U.S. patent application Ser. No. 10/072,826 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,979,193;

U.S. patent application Ser. No. 10/072,858 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,932,600;

U.S. patent application Ser. No. 10/072,462 filed on Feb. 5, 2002 nowU.S. Pat. No. 6,929,472;

U.S. patent application Ser. No. 10/072,852 filed on Feb. 6, 2002 nowU.S. Pat. No. 6,971,876;

U.S. patent application Ser. No. 10/072,831 filed on Feb. 6, 2002 nowU.S. Pat. No. 6,910,886;

U.S. patent application Ser. No. 10/071,847 filed on Feb. 6, 2002 nowU.S. Pat. No. 6,988,890;

U.S. patent application Ser. No. 10/073,819 filed on Feb. 11, 2002 nowU.S. Pat. No. 6,719,558;

U.S. patent application Ser. No. 10/073,822 filed on Feb. 11, 2002 nowU.S. Pat. No. 5,926,524;

U.S. patent application Ser. No. 10/073,823 filed on Feb. 11, 2002;

U.S. patent application Ser. No. 10/073,672 filed on Feb. 11, 2002 nowabandoned; and

U.S. patent application Ser. No. 10/076,128 filed on Feb. 12, 2002 nowU.S. Pat. No. 6,719,559; each of which is a continuation-in-part of eachof

U.S. patent application Ser. No. 10/016,992 filed on Dec. 13, 2001;

U.S. patent application Ser. No. 10/017,272 filed on Dec. 13, 2001 nowU.S. Pat. No. 6,783,362;

U.S. patent application Ser. No. 10/017,454 filed on Dec. 13, 2001; and

U.S. patent application Ser. No. 10/017,455 filed on Dec. 13, 2001;

each of which is a continuation-in-part of

U.S. patent application Ser. No. 09/405,373 filed on Sep. 24, 1999, nowU.S. Pat. No. 6,331,111, and priority is claimed to each of theforegoing.

Priority is also claimed to U.S. Provisional Patent Application Ser. No.60/304,324 filed on Jul. 10, 2001.

BACKGROUND

Lights that may be for activating light-activated materials aredisclosed. There are various materials that are activated by light. Forexample, dental restorative materials, dental sealants and orthodonticadhesives may include monomers and a photoinitiator. The photoinitiatormay be sensitive to light of a particular wavelength, and when exposedto light of that wavelength of sufficient power and duration, activatesthe monomers so that they polymerize into a cured and durable polymer.Further, dental whiteners may be activated or accelerated by exposure toa particular light. In the medical field, light activated materials mayinclude splints, stents, hard tissue restorations, and drugs which areactivated within the human body by exposure to a particular light. Inthe construction field, various adhesives, coatings, insulation, andsealants may be activated by particular light. A particular applicationof such technology would be the activation or curing of structural,repair or coating materials, including underwater application of suchmaterials, or application of such materials in space.

SUMMARY

Various lights and structures thereof and methods of using them aredisclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a battery-powered light that uses a single light emittingdiode chip as a light source.

FIG. 2 depicts a cross-section of the light of FIG. 1.

FIG. 3 depicts an AC-powered light that uses a single light emittingdiode chip as a light source.

FIG. 4 depicts a cross section of the light of FIG. 3.

FIG. 5 depicts a battery-powered light that uses two light emittingdiode chips as a light source.

FIG. 6 depicts a cross-section of the light of FIG. 5.

FIG. 7 depicts an AC-powered light that uses two light emitting diodechips as a light source.

FIG. 8 depicts a cross-section of the light of FIG. 7.

FIG. 9 depicts a battery-powered light that uses three light emittingdiode chips as a light source.

FIG. 10 depicts a cross-section of the light of FIG. 9.

FIG. 11 depicts an AC-powered light that uses three light emitting diodechips as a light source.

FIG. 12 depicts a cross section of the light of FIG. 11.

FIG. 13 depicts a battery-powered light that uses three or moresemiconductor chip modules mounted on a heat sink in a manner that thelight they emit is collected by a reflector apparatus and focused by alens means onto a light transport mechanism, such as a light guide,plastic stack or fiber.

FIG. 14 depicts a cross-section of the light of FIG. 13.

FIG. 15 depicts a variation of the light of FIG. 13, in the lighttransport mechanism is replace by a distally-located mirror whichreflects generally coherent light emitted from the light source in adesired direction for use.

FIG. 16 a depicts a light which uses a plurality of light emittingsemiconductor modules mounted on a heat sink as a light source, afocusing means to produce a generally coherent beam of light, and alight transport means such as optically conductive cable fortransporting light to a location remote from the light source for use.

FIG. 16 b depicts a cross section of the light of FIG. 16 a.

FIG. 17 a depicts a gross cross section of a light emitting diode chipthat uses an insulative substrate.

FIG. 17 b depicts a gross cross section of a light emitting diode chipthat uses a conductive substrate.

FIG. 18 a depicts epitaxial layers of a light emitting diode chip thatuses an insulative substrate.

FIG. 18 b depicts epitaxial layers of a light emitting diode chip thatuses a conductive substrate.

FIG. 19 a depicts a top view of a light emitting diode chip array(single chip) with an insulative substrate.

FIG. 19 b depicts a top view of a top view of a light emitting diodechip array (single chip) with a conductive substrate.

FIG. 20 a depicts a side view of a chip package for a light emittingchip that shows a light emitting diode chip with an insulative substratemounted in a well of a heat sink, with electrical connections and lightemission shown.

FIG. 20 b depicts a perspective view of a chip package for a lightemitting chip with an insulative substrate that shows a chip arraymounted in a well of a heat sink.

FIG. 21 a depicts a side view of a chip package for a light emittingchip that shows a light emitting diode chip with a conductive substratemounted in a well of a heat sink, with electrical connections and lightemission shown.

FIG. 21 b depicts a perspective view of a chip package for a lightemitting chip with a conductive substrate that shows a chip arraymounted in a well of a heat sink.

FIG. 22 a depicts a side view of a chip package for a light emittingchip mounted in a well of a heat sink according to the so-called ‘flipchip’ design, the chip having an insulative substrate.

FIG. 22 b depicts a side view of a flip chip mounted on a flip chip pad.

FIG. 22 c depicts a perspective view of a flip chip pad.

FIG. 22 d depicts a perspective view of the chip package of FIG. 22 a.

FIG. 23 depicts a side view of a flip chip package with a conductivesusbtrate.

FIG. 24 a depicts a side view of a light emitting diode chip packageincluding the chip (insulative substrate) and heat sink surface mountarrangement with a protective dome, lens or cover.

FIG. 24 b depicts a side view of a light emitting diode chip packageincluding the chip (conductive substrate) and heat sink surface mountarrangement with a protective dome, lens or cover.

FIG. 25 a depicts an array of light emitting chips with insulativesubstrates in surface mount arrangement in a single well of a heat sink.

FIG. 25 b depicts a perspective view of the array of surface-mountedchips of FIG. 25 a.

FIG. 26 a depicts an array of light emitting chips with conductivesubstrates in surface mount arrangement in a single well of a heat sink.

FIG. 26 b depicts a perspective view of the array of surface-mountedchips of FIG. 26 a.

FIG. 27 a depicts an array of light emitting chips with insulativesubstrates in surface mount arrangement in individual sub-wells of awell of a heat sink.

FIG. 27 b depicts a perspective view of the array of surface-mountedchips of FIG. 27 a.

FIG. 28 a depicts an array of light emitting chips with conductivesubstrates in surface mount arrangement in individual sub-wells of awell of a heat sink.

FIG. 28 b depicts a perspective view of the array of surface-mountedchips of FIG. 28 a.

FIG. 29 a depicts a light emitting surface mount chip package includingarray of chips, heat sink and protective dome, lens or cover accordingto the chip and surface mount configuration of FIG. 25 a above.

FIG. 29 b depicts a light emitting surface mount chip package includingarray of chips, heat sink and protective dome, lens or cover accordingto the chip and surface mount configuration of FIG. 26 a above.

FIG. 30 a depicts a light emitting surface mount chip package includingarray of chips in sub-wells, heat sink and protective dome, lens orcover according to the chip and surface mount configuration of FIG. 27 aabove.

FIG. 30 b depicts a light emitting surface mount chip package includingarray of chips in sub-wells, heat sink and protective dome, lens orcover according to the chip and surface mount configuration of FIG. 28 aabove.

FIG. 31 a depicts a side view of a single surface mount light emittingdiode chip mounted to an elongate heat sink in a manner such that lightfrom the chip is emitted at generally a 90 degree angle to thelongitudinal axis of the elongate heat sink.

FIG. 31 b depicts a bottom view of the device of FIG. 31 a.

FIG. 32 a depicts a cross-sectional side view of an elongate heat sinkhaving two light emitting semiconductor chips in surface mountconfiguration in an angled orientation in order to present overlappinglight beams for an enhanced density light footprint.

FIG. 32 b depicts a bottom view of the device of FIG. 32 a.

FIG. 33 a depicts a cross-sectional side view of an elongate heat sinkhaving three light emitting semiconductor chips mounted on it in anangled orientation in order to present overlapping light beams for anenhanced density light footprint.

FIG. 33 b depicts a bottom view of the device of FIG. 33 a.

FIG. 33 c depicts a bottom view of the heat sink of FIGS. 33 a and 33 bto permit the reader to understand the angular orientation of the lightemitting semiconductor chips.

FIG. 33 d depicts a side view of the heat sink for 3 surface mountedLED's.

FIG. 34 a depicts a light shield which may be used to shield human eyesfrom light emitting by the light.

FIG. 34 b depicts a focus lens which may be used to focus light in orderto present a denser light footprint.

FIG. 34 c depicts a light module with reflective cone installed.

FIG. 34 d depicts a reflective cone.

FIG. 35 depicts a block diagram of control circuitry that may be usedwith lights that utilize AC power.

FIG. 36 depicts by a block diagram of control circuitry that may be usedwith lights that utilize battery power.

FIG. 37 depicts a graph of electrical current input I to the lightemitting semiconductor chip(s) of the light versus time in a pulsedpower input scheme in order to enhance light power output from thechip(s) and in order to avoid light intensity dimunition due to the heateffect.

FIG. 38 depicts a graph of total light intensity output versus time inorder to permit the reader to compare light intensity output when acurrent input pulsing scheme such as that of FIG. 37 is used to atraditional continuous wave current input approach which generates aheat effect is used.

FIG. 39 depicts a spectral output of a light with several chips, thechips having different peak wavelengths.

FIG. 40 depicts overall spectral profile patterns of multi-chip lightsin which the chips output different peak wavelengths.

DETAILED DESCRIPTION

Various light systems useful for activating light-activated materialsare disclosed. The invented light systems have application in a varietyof fields, including but not limited to medicine and dentistry wherelight-activated materials with a photoinitiator are used. Aphotoinitiator may be used to absorb light of a particular wavelengthand cause polymerization of monomers into polymers.

Light-activated materials can be applied to a surface and later cured bya variety of methods. One method includes use of a single photoinitiatoror multiple photoinitiators in the light-activated material. After thelight-activated material has been placed in a desired location, light ofa wavelength that activates the photoinitiator is applied to thelight-activated material. The light activates the photoinitiator andinitiates a desired reaction, such as polymerization, activation orcuring of the light-activated material, or catalyzing a reaction. Forsome materials, in order to initiate or complete curing, the light usedmust be of a wavelength to which the photoinitiator is sensitive, thelight should be of a power level that will cause curing, and the lightshould be applied to the light-activated material for a sufficientduration of time. Although the light used to activate the photoinitiatorshould be of a wavelength to which a photoinitiator is sensitive, thelight can come from a variety of sources, including gas lasers solidstate lasers, laser diodes, light emitting diodes, plasma-arc lights,xenon-arc lights, and conventional lamps. This document discloses lightsystems that use semiconductor chips as their source of light.

FIG. 1 depicts a battery-powered light 100 that uses a single lightemitting diode chip as a light source. FIG. 2 depicts a cross-section ofthe light 100 of FIG. 1. The portable light system 100 includes a lightsource module 102 which generates light of a desired wavelength ormultiple wavelengths for activating a photoinitiator or multiplephotoinitiators and initiating curing of a light activatedlight-activated material. The light source module 102 has a light shield103 for blocking light generated by the light emitting semiconductorchip(s) 150 from reaching human eyes and skin. The apparatus 103 couldalso be configured as a lens or focusing cone for modifying thefootprint of light emitted by the light. The light emittingsemiconductor chip(s) 150 are located at the distal end of the light,and at the distal end of the light source module 102. The chip(s) 150are oriented to emit light at generally a right angle with thelongitudinal axis of the light source module or the longitudinal axis ofthe light handpiece, although chips could be mounted to emit light atfrom about a 45 degree angle to about a 135 degree angle with thelongitudinal axis of the light source module, heat sink, or handpiece asdesired. The light system 100 includes a housing 104 for containing andprotecting electronic circuits and a DC battery pack. In some lights,the light emitting semiconductor chip(s) may be powered by from lessthan about 25 milliamps to more than about 2 amps of electrical current.Many lights can have chip(s) powered from about 350 milliamps to about1.2 amps of current. Higher power lights may often use more than about100 milliamps of current.

A switch 105 a is provided on the top of the housing 104 facing adirection opposite from the direction that light would be emitted fromthe light source module 103. A second switch 105 b is provided on theside of the housing. The switches 105 a and 105 b are devices such as abutton or trigger for turning the light emission of the light on andoff. A timer 106 is provided to control the duration of time that thelight emits a beam of light. Control buttons to set and adjust the timerare depicted as 151 a and 151 b.

An audible indicator or beeper may be provided in some lights toindicate when light emission from the light begins and ends. A firstlight emitting diode indicator lamp 107 is located on the housing in avisible location in order to indicate to the user low battery power. Asecond light emitting diode indicator lamp 108 is located on the housingin a visible location in order to indicate to the user that the batteryis being charged. A main on/off switch to the light 160 is provided atthe rear or proximal end of the housing. A wavelength selector may beprovided in some lights so that the user may select the wavelength oflight that he wishes to emit from the light, depending on the wavelengthsensitivity of the photoinitiator in the light-activated material thathe is using. The user may also select a combination of two or morewavelengths of light to be emitted together in some lights.

A separate battery charger module 109 may be included in order toreceive AC power from a traditional wall socket and provide DC power tothe light system for both charging the batteries and powering the lightsource and control circuitry when the batteries if desired. The batterycharger module 109 has a cable 109 a and a plug 109 b for plugging intoa receptacle or connector 170 on the proximal end of the light housing104. The battery charger module 109 includes circuitry 109 c forcontrolling battery charging of batteries 166.

The light module 102 has a casing 161 that encases an elongate heat sink162. The casing 161 is separated from the heat sink 162 by a bufferlayer 163 such as insulation tape and an air space or air jacket may beprovided therebetween for heat dissipation. Electrically conductivewires 164 to power the light-emitting semiconductor chip(s) 150.Internally, we can see that the heat sink 162 is an elongate and curvedstructure which positions a semiconductor chip at its end in aconvenient place for use without a light guide. At the distal end of theheat sink 162, there may be a smaller primary heat sink or semiconductorchip module which includes a smaller primary heat sink. A semiconductormodule may be covered by a protective cover or dome or a focus lens. Theheat sink 162 may be an elongate structure or other shape as desired.Use of an elongate heat sink 162 rapidly transfer heat away from thechip(s) 150 for heat dissipation. If heat transfer and dissipation arenot handled adequately, damage to the chip(s) 150 may result, or lightoutput of the chip(2) 150 may be diminished.

The light source module 102 is removable from the housing 104 andinterfaces therewith and mounts thereto by a connection plug 165. One ormore batteries 166 are provided to power the light during use. The lightmay have control circuitry 167 located in the housing 102. Batterycharger 109 c is located in the power supply 109 for controlling batteryrecharging and direct powering of the light from wall outlet power whenthe batteries are low. The power supply 109 has an AC plug 109 d.

A unique advantage of some of the light systems depicted herein is thatmost or all components of the light system, including the light source,batteries, control circuitry and user interface, are convenientlylocated in or on a handpiece. This results in a very portable, yetcompact and easy to use light system. Only when the batteries are beingcharged would the user need to have a cord attached to the light systemor even be in the vicinity of AC power. In the case of a battery-lesslight system, the batteries would be omitted and the light system wouldbe connected to a power source by an electrical cord. It would also bepossible for the light system to be operated using power from a batterycharger when the battery pack is being charged or when no batteries arebeing used.

FIG. 3 depicts an AC-powered light that uses a single light emittingdiode chip as a light source. FIG. 4 depicts a cross section of thelight of FIG. 3. Referring to these figures, a light system 301 isdepicted. The light system 301 includes a handpiece or wand 302, cabling303, and a power supply 304 with an AC plug 304 a. Light controlcircuitry 304 b may be located within the power supply 304 and is remotefrom the wand 302 in order to keep the wand compact and light weight.The handpiece or wand 302 has minimum size, weight and componentry forconvenience of use. The handpiece 302 includes a housing 305, an on/offswitch or light output control 306, an integral light source module 307,and a device 309 which may be a light shield, light reflective cone orfocus lens. The handpiece 302 receives electrical power from cabling303. A cable strain relief device 308 may be provided. A timer 310 maybe provided with timer adjustment buttons 311 and 312 in order tocontrol timed duration of light output from the light. All controlcircuitry 304 b is located in a module remote from the handpiece 302.

Referring to the cross section of FIG. 4, it can be seen that the heatsink 401 may be configured as an elongate device with a planar mountingplatform on its distal end for mounting chips or chip modules thereto.The heat sink has a longitudinal axis, and the light emittingsemiconductor chip(s) may be oriented at an angle with the longitudinalaxis of the heat sink from about 45 to about 135 degrees. In somelights, the chips may be oriented to emit light at an angle with theheat sink longitudinal axis of 70 to 110 degrees, 80 to 100 degrees, orabout 90 degrees. The heat sink distal end may be curved as desired toposition a light emitting semiconductor device 401 thereon to bepositioned in a location for convenient use. The semiconductor device402 may be covered with a protective window, dome or focus lens 403. Theheat sink may occupy less than 50% of the length of the wand, more than50% of the length of the wand, 60% of the length of the wand, 70% of thelength of the wand, 80% of the length of the wand, 90% of the length ofthe wand, or up to 100% of the length of the wand. Electrical wire 404provides power to the light emitting semiconductor device 402.Insulation means or insulators 405 such as rubber insulators orinsulation tape separate the heat sink 401 from the casing 305 andprovide for airspace or an air jacket 406 therebetween for ventilationand heat dissipation. The insulators may be of any suitable materialthat will provide spacing and distance between the heat sink and thecasing or housing to form an air jacket therebetween and permit aircirculation, ventilation and heat dissipation. The insulators could berubber, silicone, plastic or other materials. The light housing may haveone or more vents to permit or encourage air to travel from outside thehousing into the air jacket, and/or to permit or encourage air from theair jacket to travel outside of the housing. Air exchange can assist incooling functions. The air jacket can assist in avoiding a buildup ofheat in the handpiece, wand or housing that could cause user discomfort.

FIG. 5 depicts a battery-powered light 501 that uses two light emittingdiode chips as a light source. FIG. 6 depicts a cross-section of thelight 501 of FIG. 5. The light 501 includes a housing or casing 502 forcontaining and protecting the light components. A series of vents 503are provided in the housing 502 to permit heat to escape therefrom andto permit air circulation therein. At the distal end of the housing 502,a light module 504 is provided. The light module 504 may include anangled tip and may be removable and replaceable with other light modulesof differing characteristics as desired. A light shield, lightreflective cone or focus lens 505 is provided at the distal end of thelight module 504. At the proximal end of the light 501, a handle 506 isprovided for grasping the light. An on-off switch or trigger 507 isprovided on the distal side of the light handle 506 for effecting lightemission. On the proximal side of the light handle 506, a main switch507 for powering up the light 501 is located. A timer 509 with timeradjustment buttons 510 and 511 is provided to time the duration of lightoutput. Indicator lights 512 and 513 are provided to indicate lowbattery and battery charging. A battery charger module 520 is providedwith a power supply 521, cable 522 and plug 523. The plug fits intoreceptacle 601 for charging the battery 602 of the light 501.

Referring to FIG. 6, light module 504 includes a casing 603 thatcontains an elongate heat sink 604 that is separated from the casing 603by insulators 605 to form a ventilating and heat-dissipating air space606 therebetween. Heat sink 604 may include a thermoelectric coolermaterial 608 thereon for enhanced heat dissipation. Electrical wires 607power a pair of light emitting semiconductor devices or modules 609 aand 609 b. The semiconductor devices 609 a and 609 b are mounted on theheat sink 604 at a mounting receptacle 611 that has two adjacent angledplanes oriented to cause the light output beams from the semiconductordevices 609 a and 609 b to overlap to provide an overlapped and enhancedintensity light footprint 610. The mounting planes are oriented at anangle of from about 10 to about 180 degrees with respect to each other.The light 501 also includes a timer 509 with timer control buttons 621and 622, and electronic control circuitry 623. A battery pack 602 islocated inside casing 502 to provide operating power. The light module504 is connected to housing 502 using an electrical plug 624. The lightmodule 504 can therefore be unplugged and replaced with another lightmodule of different power characteristics or which emits a differentwavelength of light for different usage applications.

FIG. 7 depicts an AC-powered light 701 that uses two light emittingdiode chips as a light source. FIG. 8 depicts a cross-section of thelight 701 of FIG. 7. The light system 701 includes a handpiece or wand702, cabling 703, and a power supply 704 with an AC plug 704 a. Controlcircuitry 704 b is located within the power supply 704 and is remotefrom the wand 702 in order to keep the wand compact and light weight.The handpiece or wand 702 has minimum size, weight and componentry forconvenience of use. The handpiece 702 includes a housing 705, an on/offswitch or light output control 706, an integral light source module 707,and a light shield 709. The handpiece 702 receives electrical power fromcabling 703. A cable strain relief device 708 may be provided. A timer710 may be provided with timer adjustment buttons 711 and 712 in orderto control timed duration of light output from the light. All controlcircuitry 704 b is located in a module remote from the handpiece 702.Referring to the cross section of FIG. 8, it can be seen that the heatsink 801 may be configured as an elongate device with a longitudinalaxis shared with the longitudinal axis of the wand. The light emittingsemiconductor chip 802 and 803 are mounted to the heat sink 801 at anacute angle to each other in order to produce an overlapping andenhanced intensity light footprint. The heat sink distal end may becurved as desired to position the light emitting semiconductor devicesthereon for convenient use. The semiconductor devices 803 and 803 may becovered by a protective window, dome or focus lens. The heat sink mayoccupy less than 50% of the length of the wand, more than 50% of thelength of the wand, 60% of the length of the wand, 70% of the length ofthe wand, 80% of the length of the wand, 90% of the length of the wand,or up to 100% of the length of the wand. Electrical wire 804 providespower to the light emitting semiconductor devices 802 and 803.Insulation means 805 such as rubber insulators or insulation tapeseparate the heat sink 801 from the casing 705 and provide for airspace806 therebetween for ventilation and heat dissipation. A connection plug810 is provided for connecting the power module to the light.Thermoelectric cooler material 820 is optionally provided on the heatsink for enhanced cooling.

FIG. 9 depicts a battery-powered light 901 that uses three lightemitting diode chips or modules as a light source. FIG. 10 depicts across-section of the light 901 of FIG. 9. The componentry of this lightis as generally described previously except for its three light emittingdiode light source structure. It uses three light emitting diode chipsor chip modules 902 a, 902 b and 902 c arranged in complementary angledconfiguration so that the light beams emitted by each overlap at adesired distance from the light source to form an overlapped andenhanced intensity light footprint 903. The arrangement of 3 LED's isdescribed elsewhere in this document.

FIG. 11 depicts an AC-powered light 1101 that uses three light emittingdiode chips or modules as a light source. FIG. 12 depicts across-section of the light 1101 of FIG. 11. The componentry of thislight is as generally described previously except for its three lightemitting diode light source structure. It uses three light emittingdiode chips or chip modules 1102 a, 1102 b and 1102 c arranged incomplementary angled configuration so that the light beams emitted byeach overlap at a desired distance from the light source to form anoverlapped and enhanced intensity light footprint 1103.

FIG. 13 depicts a battery-powered curing 1301 light that uses aplurality of semiconductor chip modules mounted on a heat sink in amanner that the light they emit is collected by a reflector apparatusand focused by a lens means onto a light transport mechanism, such as alight guide, plastic stack or fiber 1302. FIG. 14 depicts across-section of the light 1301 of FIG. 13. Many of the components ofthis light are as discussed previously for other lights, and thatdiscussion is not repeated here. However, the light source and lighttransport means are very different from lights discussed above. Thelight 1301 includes a housing 1303 which has a light transport means1302 such as a light guide, plastic stack or fiber attached to it. Thelight transport means 1302 transports light from a light module to aremote location for use. The light transport means 1302 depicted has acurved distal portion 1304 to cause light 1305 to be emitted in adesired direction, such as at a right angle to the longitudinal axis ofthe light or the light transport means. The light transport means may beremovable and replaceable with light guides of different lengths andconfigurations. A gross or secondary heat sink 1405 is provided for heatremoval from the system. The secondary heat sink 1405 has a proximalside on which a thermoelectric material layer 1406 may be placed toenhance heat removal ability. Optionally, a fan 1407 may be provided toimprove heat removal efficiency, and vents may be provided in thehousing to encourage air circulation. The secondary heat sink 1405 mayhave mounted directly or indirectly to it a plurality of semiconductorlight emitting chips or chip modules 1409. Those chips 1409 may bemounted to a primary heat sink such as 1410, light emitted by the chips1409 will be reflected by a reflector device 1411 such as a mirroredparabolic reflector to an optional lens or focusing device 1412 whichfocuses a generally coherent light beam onto the light transport means1302. The reflector may be of a desired shape for directing light, suchas frusto-conical, parabolic or otherwise. If the light emitting devicesare oriented so that the light which they emit is substantially directedtoward the distal end of the light, the reflector may be omitted. Abattery pack 1415 and control circuitry 1413 are provided.

FIG. 15 depicts an alternative configuration of the light of FIG. 13.The light 1501 has no light transport mechanism and instead has a lightexit tube 1502 that has a distal end with a mirror or reflector 1504which can reflect a generally coherent light beam 1503 to a light exit1505 in a desired direction for use, such as at a generally right angleto the longitudinal axis of the light module or the light.

FIG. 16 a depicts a light light 1601 that has a light source and controlmodule 1602 remotely located from a handpiece 1603 connected by aconnection means 1604 that includes an optically conductive cable andelectrical wires for electrical connection. FIG. 16 b depicts a crosssection of the light of FIG. 16 a. The light source and control module1602 includes a housing 1610 with optional air vents thereon, electroniccontrol circuitry 1611, an electrical cord with power plug 1612, acooling fan 1613 for air circulation and heat dissipation, a heat sink1615 which may be appropriately shaped to accept light emittingsemiconductor devices on its distal side, such as having a concavehemispherical or parabolic portion, and having a thermoelectric cooler1616 on its proximal side for enhanced heat dissipation. A plurality oflight emitting semiconductor devices such as LED chip modules 1618 aremounted to the heat sink distal side so that they emit light into anoptical system such as a focus lens 1619 which places a generallycoherent light beam onto the optically conductive cable where it istransported to a distant handpiece 1603 that includes a housing 1651,light exit 1650 for permitting light to be delivered to alight-activated material to be cured, and various controls such as lighton/off control 1660, timer display 1663, and timer adjustment buttons1661 and 1662. The distal end of the handpiece housing 1670 may beangled from the longitudinal axis of the handpiece in for convenience oflight application to a light-activated material. The remote light sourceemployed by the light in FIGS. 16 a and 16 b permit a larger and veryhigh power light source, such as one which provides 800 mw/cm² to 2000mw/cm² output from the handpiece.

As desired in various lights, the light source may be a single LED chip,single LED chip array, an array of LED chips, a single diode laser chip,an array of diode laser chips, a VCSEL chip or array, or one or more LEDor diode laser modules. The wavelength of light emitted from thesemiconductor light source can be any desired wavelength or combinationof different wavelength, depending on the sensitivity of thephotoinitiator(s) in the light-activated material to be cured. Any ofthe semiconductor and heat sink arrangements described herein may beused to construct desired lights.

Referring to FIG. 17 a, a light emitting diode (“LED”) chip 1701 isdepicted in which the LED structure 1702 has been grown on top of or onone side of an insulative substrate 1703. Electrodes 1704 a and 1704 bare provided to power the LED. In such a structure, all electrodes willbe located on the top surface of the LED. light is emitted from allsides of the LED as depicted.

A similar LED chip 1710 with a conductive substrate 1711 andaccompanying LED structure 1712 and electrodes 1713 and 1714 is depictedin FIG. 17 b.

FIG. 18 a depicts an example of epitaxial layer configuration 1801 foran LED with an insulative substrate used in lights depicted herein. TheLED includes an electrically insulative substrate such as sapphire 1802.The substrate serves as a carrier, pad or platform on which to grow thechip's epitaxial layers. The first layer placed on the substrate 1802 isa buffer layer 1803, in this case a GaN buffer layer. Use of a bufferlayer reduces defects in the chip which would otherwise arise due todifferences in material properties between the epitaxial layers and thesubstrate. Then a contact layer 1804, such as n-GaN, is provided. Acladding layer 1805 such as n-AlGaN Sub is then provided. Then an activelayer 1806 is provided, such as InGaN multiple quantum wells. The activelayer is where electrons jump from a conduction band to valance and emitenergy which converts to light. On the active layer 1806, anothercladding layer 1807, such as p-AlGaN is provided that also serves toconfine electrons. A contact layer 1808 such as p+ GaN is provided thatis doped for Ohmic contact. The contact layer 1808 has a positiveelectrode 1809 mounted on it. The contact layer 1804 has a negativeelectrode 1810.

FIG. 18 b depicts epitaxial layer configuration 1850 for an LED with aconductive substrate. The LED includes an electrically conductivesubstrate such as SiC 1852 that has an electrode 1851 on it. Thesubstrate serves as a carrier, pad or platform on which to grow thechip's epitaxial layers, and as a negative electrode in the chip. Thefirst layer placed on the substrate 1852 is a buffer layer 1853, such asn-GaN. A cladding layer 1854 such as n-AlGaN is provided followed by anactive layer 1855 such as InGaN with multiple quantum wells. That isfollowed by a cladding layer 1856 such as p-AlGaN and finally a contactlayer 1857 such as p+ GaN that has an electrode 1858 mounted on it.

FIG. 19 a depicts a top view of a single chip array, such as an LED chiparray on a single chip 1901 (in contrast with an array of single chips)with a size a×b on an insulating substrate. The size of a and b may eachbe greater than 300 micrometers, or may each be greater than 1millimeter if desired. Semiconductor materials 1904 are located on anelectrically insulative substrate (not shown). Positive and negativeelectrode pads are provided, each in electrical connection with itsrespective metal electrode strip 1902 and 1903 arranged in a row andcolumn formation (8 columns shown) to create the array and power thechip. This structure enables the LED to emit light of greater power thanthat which is possible in a non-array traditional chip. The electrodelayout of FIG. 19 a is called a ‘comb’ layout.

FIG. 19 b depicts a top view of an semiconductor chip array, such as anLED chip array, on a single chip 1950 with a size a×b, on a conductivesubstrate. Each of sizes a and b may greater than 300 micrometers, or asdesired, each of a and b may be greater than 1 millimeter. Semiconductormaterials 1952 are located on an electrically conductive substrate (notshown). Positive electrode pads are provided in electrical connectionwith a metal strip 1951 arranged in an array formation to power thechip. The substrate serves as the negative electrode in this depiction.When LED arrays, or chip arrays (as opposed to an array of chips) suchas those depicted are used in a curing light, the light source may be asingle chip array, a pair of chip arrays, or multiple chip arrays suchas 3 or more chip arrays. The chip arrays may be designed to output anyparticular desired wavelength and intensity level of light.

Referring to FIG. 20 a, a side view of a surface mount LED chip package2000 including the LED chip 2001 on a heat sink 2002 is provided. TheLED chip depicted has an insulating substrate and is mounted in a well2004 of the heat sink 2002 by the use of heat conductive and lightreflective adhesive 2003. light is emitted by the chip in alldirections, and light which is emitted toward the adhesive 2003 or thewell walls is reflected outward in a useful direction 2020. The chip iselectrically connected via wires 2010 a, 2010 b, 2010 c and 2010 d usingintermediary islands 2011 and 2012. The LED chip is located in acircular well 2004 of the heat sink 2002. The circular well is formedwith sides or walls at about a 45 degree angle or other desired angle(such as from about 170 to about 10 degrees) so that light emitted fromthe side of the chip will be reflected from the walls of the well in adesired direction as indicated by arrows in the figure. This allows thehighest possible light intensity to be obtained using a chip of givensize. The well walls may have a light reflective coating to increaseefficiency.

Referring to FIG. 20 b, a perspective view of a LED chip array (singlechip) chip package 2050 including the chip array 2051 on an insulativesubstrate in a well 2052 of a heat sink 2053 is depicted.

Referring to FIG. 21 a, a side view of an LED chip module 2100 isprovided. An LED chip 2101 with a conductive substrate is mounted in acircular well 2103 of a heat sink 2104 by use of heat conductive lightreflective adhesive 2102. A negative electrode 2110 is provided on theheat sink. Positive electrical connection is provided by wires 2105 and2106, and island 2107.

Referring to FIG. 21 b, a chip array package 2150 that includes an LEDchip array 2151 with a conductive substrate mounted in a well 2152 of aheat sink 2153 with an electrode 2154 and wire connection 2155 isdepicted.

FIG. 22 a depicts a side view of a chip package 2200 for a lightemitting diode chip array 2201 mounted in a well 2202 of a heat sink2203 according to the so-called ‘flip chip’ design, the chip having aninsulative substrate. FIG. 22 b depicts a side view of a flip chip 2201mounted on a flip chip pad 2204. FIG. 22 c depicts a perspective view ofa flip chip pad 2204. FIG. 22 d depicts a perspective view of the chippackage 2200 of FIG. 22 a. Intermediate islands or electrode pads 2201 aand 2210 b are provided on the flip chip pad to ease of electricalconnection with the chip. Electrode bumps 2111 a and 2111 b are providedbetween the chip and the pad for electrical connection. The chip has anelectrode 2201 b on top and its epitaxial layers 2201 a facing downtoward the pad 2204 and the bottom of the well 2202. The pad 2204 uppersurface is light reflective so that light is reflected from the pad in auseful direction. The pad 2204 may be coated with a light reflectivefilm, such as Au, Al or Ag. In such a package, all of the light emittedfrom the chip can be reflected back in the light exit direction forhighest light output.

FIG. 23 depicts a flip chip package 2301 in which a chip 2302 with aconductive substrate is mounted upside down (electrode up) on a flipchip pad 2303 with light reflective and heat conductive adhesive 2304 inthe well of a heat sink. Electrical connection takes advantage of theexposed electrode of the chip 2302.

Referring to FIG. 24 a, a high power LED package 2401 is depicted usinga chip 2402 with an insulative substrate mounted in the well of a heatsink 2403 using heat conductive and light reflective adhesive 2404. Theheat sink is surrounded by a known insulating material 2405 that servesthe purpose of protecting electrode and dome connections. The walls andbottom of the well may be polished to be light reflective, or may becovered, plated, painted or bonded with a light-reflective coating suchas Al, Au, Ag, Zn, Cu, Pt, chrome, other metals, plating, plastic andothers to reflect light and thereby improve light source efficiency.Electrodes and/or connection blocks are provided for electricalconnection of the chip. An optical dome or cover 2410 may optionally beprovided for the purpose of protecting the chip and its assemblies, andfor the purpose of focusing light emitted by the chip. The dome may bemade of any of suitable material such as plastic, polycarbonate, epoxy,glass and other suitable materials. The configuration of the well andthe dome provide for light emission along an arc of a circle defined byφ. The dome 2410 may serve the function of protecting the chip(s) fromdirt, moisture, contaminants and mechanical damage. It may also servethe function of focusing light emitted by the chip(s) or otherwisemodifying the light beam to a desired configuration or footprint. FIG.24 b depicts a similar arrangement for a chip package 2450 in which thechip 2454 has a conductive substrate and thus when mounted to the heatsink 2452 can use an electrode 2455 on the heat sink itself forelectrical connection. Protective dome 2451 and insulating covering 2453are provided.

Referring to FIGS. 25 a and 25 b, a chip package 2501 is provided withan array of light emitting semiconductor chips 2504 a, 2504 b, etc.having electrically insulative substrates located in a single well 2502of a heat sink 2503. The chips are mounted by an electrically conductiveand heat conductive adhesive 2605. The chips are electrically connectedto each other by wires 2505 a, 2505 b, etc.

Referring to FIGS. 26 a and 26 b, a chip package 2601 is provided thathas a heat sink 2602 with a single well 2603 and an array of LED chips2604 a, 2604 b, etc. in the well 2603. The chips have electricallyconductive substrates and an electrode 2606 is provided on the heatsink.

Referring to FIG. 27 a, a chip package 2701 is depicted with an array ofLED chips 2702 a, 2702 b, 2702 c, etc. is depicted, with each chiplocated in its own individual sub-well 2703 a, 2703 b, 2703 c in a grosswell 2704 of a heat sink 2705. The chips have electrically insulativesubstrates.

Referring to FIG. 27 b, a chip package 2750 is depicted that has anarray of LED chips 2763 a, 2763 b, 2763 c with electrically conductivesubstrates. Each LED chip is mounted in its own individual sub-well, alllocated within a gross well 2761 of a heat sink 2762.

FIGS. 28 a and 28 b depict a chip package 2801 that has a heat sink 2802with a gross well 2803 and a plurality of sub-wells 2804 therein, eachsub-well having a light emitting chip 2805 with a conductive substratewithin it. The heat sink 2803 has a negative electrode 2806 forelectrical connection.

Referring to FIG. 29 a, an LED chip module 2901 is depicted that has anarray of LED chips 2902 a, 2902 b, etc located in a well 2903 of a heatsink 2904. Insulative covering 2910 as well as a cover or dome 2911 areprovided respectively. The chips of FIG. 29 a have insulativesubstrates.

Referring to FIG. 29 b, an LED chip module 2950 is depicted that has anarray of LED chips 2951 a, 2951 b, etc. located in a well 2955 of a heatsink 2954. Insulative covering 2960 as well as a cover or dome 2961 areprovided respectively. The chips of FIG. 29 b have conductive substratesand an electrode 2959 is provided on the heat sink.

Referring to FIG. 30 a, an LED chip module 3001 is depicted that has anarray of LED chips 3002, with each chip in a sub-well 3003 of a grosswell 3006 of a heat sink 3005 and the entire module covered by aprotective or focus dome 3012. The chips have electrically insulativesubstrates.

Referring to FIG. 30 b, an LED chip module 3050 is depicted that has anarray of LED chips 3051, with each chip in a sub-well 3052 of a grosswell 3055 of a heat sink 3054 and the entire module covered by aprotective or focus dome 3061. The chips have electrically conductivesubstrates and there is an electrode 3056 on the heat sink.

Referring to FIGS. 31 a and 31 b, side and bottom views of a surfacemount chip configuration are depicted for mounting a single LED 3100 orLED module (as described previously) to an elongate heat sink 3101.Electrically conductive wires 3102 a and 3102 b and electrodes 3103 aand 3103 b are provided for powering the LED. The LED is mounted on aplatform 3104 formed on the heat sink distal end. Mounting is achievedby use of light reflective and heat conductive adhesive 3105. A cover orfocus dome 3106 is provided over the LED. The heat sink has alongitudinal axis, and the LED is mounted so that the average beam oflight that it emits is generally at a 45 to 135 degree angle with thataxis, and in some instances at a right angle to it.

FIGS. 32 a and 32 b depict side and bottom views of an elongate heatsink 3201 having two light emitting semiconductor chips or modules 3202and 3203 mounted on mounting platforms 3204 a and 3204 b using adhesive3205 a and 3505 b (such as heat conductive or light reflectiveadhesive). The chips are mounted on the heat sink in an angledorientation with respect to each other in order to present overlappinglight beams for an enhanced density light footprint 3204. The angle oforientation of the chips is depicted as θ which can be from zero to 180degrees, or from 30 to 150 degrees, or from 45 to 135 degrees, or from70 to 110 degrees, or from 80 to 100 degrees or about 90 degrees, asdesired. The chips are offset from each other by a desired distance ‘a’,which can range from zero to any desired distance. Wires and electrodesare provided to power the LED's. An optional thermoelectric cooler 3208may be provided to enhance heat removal.

FIG. 33 a depicts a cross-sectional side view of a light module thatuses three light emitting chips or chip modules. FIG. 33 b depicts abottom view of the same. FIG. 33 c depicts a bottom view of the heatsink and mounting platform arrangement. FIG. 33 d depicts a side view ofthe heat sink and mounting platform arrangement. An elongate heat sink3301 is provided having three light emitting semiconductor chips ormodules 3302, 3303, and 3304 mounted on mounting platforms in an angledorientation with respect to each other in order to present overlappinglight beams for an enhanced density light footprint 3306. The mountingplatforms depicted are generally planar and are arranged to present thedensest useful light footprint. The modules may each include their ownprimary heat sink. The modules or chips may be mounted to the elongateheat sink using a heat conductive or light reflective adhesive asdesired. Electrical wires and electrodes are used to power the chips ormodules. An optional thermoelectric cooler 3308 may be provided. Themounting platforms 3305 a, 3305 b and 3305 c can be seen more clearly inFIGS. 33 c and 33 d. The mounting platforms depicted are arranged incircular fashion at an angular offset θ with respect to each other,which in this case is 120 degrees. More mounting platforms could beused, and any desired arrangement of the mounting platforms could beaccommodated. In FIG. 33 d it can be seen that the mounting platforms3305 a, 3305 b and 3305 c are arranged at an angle φ with thelongitudinal axis of the heat sink 3301. The angle φ can be from 0 to 90degrees, from 10 to 80 degrees, from 20 to 70 degrees, from 30 to 60degrees, from 40 to 50 degrees, or about 45 degrees as desired togenerate the densest usable light footprint.

FIG. 34 a depicts a light shield 3401 which may be used in conjunctionwith lights depicted herein to shield human eyes from light emitting bythe light. The light shield includes an orifice 3403 through which lightfrom a light may pass, the receptacle 3403 being formed by the lightshield body 3402. A flare 3404 of the shield performs most of theprotective function.

FIG. 34 b depicts a focus lens 3402 which may be used to focus lightemitted by lights depicted herein in order to present a denser lightfootprint. The focus lens has an outer periphery 3405, a light entranceside 3506 and a light exit 3507. The focus lens may be designedaccording to known optical principles to focus light output from chipswhich may not be in an optimal pattern for use in curing.

FIG. 34 c depicts a reflection cone 3408 in conjunction with LED module3409, which is mounted on a heat sink 3910 by using heat conductiveadhesive 3411. One or more connection wires 3412 may be provided topower the LED module 3409. The purpose of the light reflective cone isto re-shape the light beam from the LED module to create a lightfootprint of desired size and density. The inner wall of the cone 3408may be coated with a highly reflective material, such as the reflectivematerials mentioned elsewhere in this document. The light beam from theLED module will change its path and configuration due to being reflectedby the cone 3408.

A detailed depiction of the light reflective cone 3408 is provided inFIG. 34 d, which illustrates a cross-sectional view of the cone. Anopening with an appropriate diameter “a” is provided at the proximalside of the cone for fitting to a light module of a light. The diameter“a” is chosen as an appropriate size for permitting light to entertherein. The cone has a total length “b”. Adjacent light entrance at“a”, a cylindrical portion of the cone is provided having a longitudinallength “c”. Following cylindrical portion “c”, there is a frusto-conicalsection of the cone interior having a length “b” minus “c”. A light exitis provided at the end of the cone opposite the light inlet. The lightexit has a diameter “d”, where in many lights, “d” will be smaller than“a”. The exterior diameter of the cone at its point of attachment to alight module is “e”, where “e” is greater than “a”. As desired, thevarious dimensions of the cone as well as its basic geometry (such asconical, frusto-conical, cylindrical, parabolic, etc.) are selected toachieve a desired light footprint size and density. At least someportion of the interior surfaces of the reflective cone may have theability to reflect light to aid in increasing the density of a lightfootprint. Appropriate reflective surfaces are mentioned elsewhereherein. Example dimensions of the various portions of the reflectivecone in one light are as follow: a=from about 5 mm to about 8 mm; b=fromabout 5 mm to about 8 mm; c=from about 2 mm to about 3 mm; d=from about4 mm to about 6 mm; e=from about 8 mm to about 10 mm. Actual structureand dimensions of a reflective cone or reflective attachment or lightexit for a light may vary depending on product type and application anddesign choice.

FIG. 35 depicts a logic diagram 3501 of circuitry that may be used byAC-powered versions of the invented lights. AC power input 3502 isprovided to a power switch source 3503 which outputs DC power to a mainswitch 3504. Main switch 3504 powers the control circuit 3505 and theoptional TE cooler 3506 if so equipped. Main switch 3504 also provides aconstant current source 3507 for the timer 3508, timer setup 3511, timeractivation switch 3572 and optional light output beeper 3513. Constantcurrent source 3507 also powers the light source 3509 to accomplishlight output 3510.

Referring to FIG. 36, a logic diagram 3601 of circuitry that may be usedby battery-powered versions of the invented lights is depicted. AC powerinput 3602 is provided to a power switch source 3603 which outputs DCpower to a battery charge unit 3604 that charges battery 3605. Thebattery 3605 powers main switch 3507. Main switch 3607 powers thecontrol circuit 3608 that controls the optional TE cooler 3610 and thefan 3609. Main switch 3607 also provides a constant current source 3611for the timer 3613, timer setup 3614, timer activation switch 3615 andoptional light output beeper 3616. Constant current source 3611 alsopowers the light source 3612 to accomplish light output. An electricalvoltage booster 3617 may be provided to increase the voltage from thebattery to meet electrical requirements of the light source.

Referring to FIG. 37, a graph of electrical current input I to the lightemitting semiconductor chip(s) of the light versus time in a pulsedpower input scheme is depicted. FIG. 38 depicts a graph of total lightintensity output versus time in order to permit the reader to comparelight intensity output when a current input pulsing scheme such as thatof FIG. 37 is used to a traditional continuous wave current inputapproach which generates a heat effect is used. A pulsed current inputscheme may be used in order to enhance light power output from thechip(s) and in order to avoid light intensity reduction due to the heateffect. It has been found that when operated in continuous wave mode,the heat effect or heat buildup in the light emitting semiconductorchips will cause a decrease in light output intensity over time, until astabilized light output yield is reached 3802 at point in time 3803. Incontrast, when current input to the semiconductor light source ispulsed, a greater even level of light power output with greaterintensity is achieved 3801. Laboratory experiments have shown thisincrease “d” to be more than 20% in lights, providing significantlyincreased light yield and stable light intensity output in exchange fora simple control modification. Each of the square waves in FIG. 37 is apulse of current input to the semiconductor light source, measured by“a=duration”, “b=rest period”, and “c=current input level (amps.)”.These criteria can be adjusted depending on the curing environment, orpulsed current input to the light source could be omitted in favor ofcontinuous wave current input. It has also been found that pulsed poweroutput from the light (not shown in the figures) may be desirable insome circumstances. Pulsed power output from the light can avoidoverloading photoinitiators in the material to be cured with photons,and permitting them to initiate polymerization of a light-activatedmaterial in a stable fashion.

Referring to FIG. 39, a graph showing the spectral output of a lightwith numerous chips, the chips having differing peak spectral outputs,is provided. Some light-activated materials, such as dental compositesmay include more than one photoinitiator. The photoinitiators may besensitive to light of different wavelengths. Even though light emittedby single semiconductor chip can cover many photoinitialtors, a singlesemiconductor chip may not provide broad enough spectral output to coverthe full range of possible photoinitiators that may be present in aparticular light-activated material. Referring to previous figures, itis possible to construct a curing light that has numerous light-emittingsemiconductor chips, at least several of which have differing spectraloutputs, such as is depicted in FIG. 39. For example, LED1 could peak atabout 325 nm, while LED2 peaks at about 350 nm, etc. to LED n whichpeaks at 575 nm. Of course many other configurations and spectraloutputs are possible depending on the particular use of the light. Thearrangement of the light emitting semiconductor chips can be variedaccording to the light beam pattern needed.

Depending on number and type of light emitting semiconductor chips used,per FIG. 39, an overall spectrum profile pattern, such as Profile 1,Profile 2, and Profile n of FIG. 40 can be achieved. These particularspectral profiles are provided by way of example only. On the spectrumProfile n, there are two cutoff wavelengths λ₁ and λ₂. λ₁ and λ₂ will beselected to be the desired wavelength range for a particular class orset of light-activated materials for which the light may be used, andthe light will be able to activate light-activated materials sensitiveto light between λ₁ and λ₂. For example, a light source with λ₁=400 nmand λ₂=460 nm might provide an appropriate light spectra for activatingcurrent dental materials. The spectrum profile has two intensitiesrelative to cut off wavelength, I₁ and I₂. The value of I₁ and I₂ can beI₁>I₂, I₁<I₂ or I₁=desired. The spectrum profile between I₁ and I₂ canbe linear, parabolic and others, as desired.

If desired, a curing light can be constructed per FIGS. 39 and 40 inwhich the peak spectral output of most or each chip is in the range ofbetween 200 and 455 nanometers, so that λ₁>=200 nm and λ₂<=455 nm.Another variation would place λ₁>=300 nm and λ₂<=455 nm. Light intensityoutput from each chip can be as desired, such as 40 mW or more, and insome configurations intensity I₁ and I₂ will both equal or exceed 40 mW.There is no upper limit for light intensity other than ordinaryengineering constraints.

Heat sinks are often a combination of two different kinds of materials,the first with a low thermal expansion rate and the second with highthermal conductivity. Monolithic heat sinks may be used as well.Examples of some heat sink materials which may be used in lightsdepicted herein include copper, aluminum, silver, magnesium, steel,silicon carbide, boron nitride, tungsten, molybdenum, cobalt, chrome,Si, SiO₂, SiC, AlSi, AlSiC, natural diamond, monocrystalline diamond,polycrystalline diamond, polycrystalline diamond compacts, diamonddeposited through chemical vapor deposition and diamond depositedthrough physical vapor deposition, and composite materials or compounds.Any materials with adequate heat conductance and/or dissipationproperties can be used. If desired, a heat sink may have fins or othersurface modifications or structures to increase surface area and enhanceheat dissipation.

Examples of heat conductive and/or electrically insulative adhesiveswhich may be used are silver based epoxy, other epoxies, and otheradhesives with a heat conductive quality and/or electrically insulativequality. In order to perform a heat conductive function, it is importantthat the adhesive possess the following characteristics: (i) strongbonding between the materials being bonded, (ii) adequate heatconductance, (iii) electrically insulative or electrically conductive ifdesired (or both), and (iv) light reflectivity if desired, or anycombination of the above. Examples of light reflective adhesives whichmay be used include silver and aluminum based epoxy. One example heatconductive and electrically insulative adhesive includes a mixture of aprimer and an activator. In this example, the primer may contain one ormore heat conductive agents such as aluminum oxide (about 20–60%) and/oraluminum hydroxide (about 15–50%). The primer may also contain one ormore bonding agents such as polyurethane methacrylate (about 8–15%),and/or hydroxyalkyl methacrylate (about 8–15%). An activator may bemixed with the primer to form an adhesive. The activator may include anydesired catalyst, for example n-heptane (about 5–50%), aldheyde-anilinecondensate (about 30–35%), isopropyl alcohol (about 15–20%), and anorganocopper compound (about 0.01 to 0.1%). Adhesives such as describedherein can be used to mount a chip to a primary heat sink, or to mount aprimary heat sink to a secondary heat sink, or both.

Examples of substrates on which the semiconductors used in the lightsdepicted herein may be grown include Si, GaAs, GaN, ZnS, ZnSe, InP,Al2O3, SiC, GaSb, InAs and others. Both electrically insulative andelectrically conductive substrates may be used.

Materials which may be used in a thermoelectric cooler in lightsdepicted herein include Bi₂Te₃, PbTe, SiGe, BeO₂, BiTeSe, BiTeSb, AlO₃,AlN, BaN and others.

The semiconductor light source of a light should emit light of awavelength suitable to activate the desired light-activated material.This may be achieved by using a semiconductor light source that emits awavelength of light to which the light-activated material is sensitive,or emitting a shorter wavelength of light at a higher power level.Laboratory testing shows that using a wavelength of light that is longerthan the wavelength to which the light-activated material is sensitiveis often not effective in activating the light-activated material.

Heat sinks used in the lights can be of a variety of shapes anddimensions, such as those depicted in the drawings or any others whichare useful for the structure of the particular light source beingconstructed. It should be noted that particular advantage has been foundwhen attaching the semiconductor light source to a small primary heatsink, and then the small primary heat sink is attached to an elongatesecondary heat sink to draw heat away from the semiconductor and awayfrom the patient's mouth.

While the present lights have been described and illustrated inconjunction with a number of specific configurations, those skilled inthe art will appreciate that variations and modifications may be madewithout departing from the principles herein illustrated, described, andclaimed. The present invention, as defined by the appended claims, maybe embodied in other specific forms without departing from its spirit oressential characteristics. The configurations of lights described hereinare to be considered in all respects as only illustrative, and notrestrictive. All changes which come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

1. A light for activating light-activated materials comprising: a wandadapted to be grasped by a human hand for use in positioning andmanipulating the light, a wand housing that is at least a portion of theexterior surface of said wand, said wand housing having a top, a bottom,a left side and a right side, an elongate heat sink located at leastpartially within said wand, said elongate heat sink having a proximalend, a distal end, and a longitudinal axis therebetween, a mountingplatform on said elongate heat sink distal end, at least onesemiconductor chip capable of emitting light of a wavelength that isuseful in activating light-activated materials, said semiconductor chipbeing located on said mounting platform at said elongate heat sinkdistal end, said mounting platform being oriented so that light emitteddirectly in front of said chip travels at an angle of 30 to 150 degreeswith respect to said longitudinal axis, a cover for covering said chip,said cover being made at least in part from a material that permitslight emitted by said chip to pass through said cover to travel to alight-activated material, a plurality of air vents on said housing, aplurality of insulators located between said heat sink and said wandhousing, an air jacket located between said heat sink and said housing,said air jacket being maintained by said insulators keeping said housingspaced apart from said elongate heat sink, said air jacket at leastpartially surrounding said heat sink, said air jacket permitting aircirculation, ventilation and heat dissipation in order to manage heatgiven off by said chip, said circulation occurring by air entering anair vent, passing through said air jacket where said air picks up heatfrom said elongate heat sink, and said air departing through an air ventto the exterior of said housing in order to dissipate heat from saidelongate heat sink.
 2. A curing light as recited in claim 1 furthercomprising a fan that draws air into said housing from the exterior ofsaid housing through a vent, forces said air through said air jacket andpast said elongate heat sink where said air picks up heat from saidelongate heat sink, and then out of said housing through a vent in orderto dissipate heat.
 3. A light for activating light-activated materialscomprising: a housing, a plurality of air vents on said housing, asemiconductor chip capable of emitting light useful in activating alight-activated material, a primary heat sink, said primary heat sinkhaving a longitudinal axis, a mounting platform on said elongate heatsink, said semiconductor chip being attached to said mounting platformon primary heat sink, said mounting platform being oriented so thatlight emitted directly in front of said chip travels at an angle of 30to 150 degrees with respect to said longitudinal axis, a secondary heatsink capable of assisting in heat dissipation, said secondary heat sinkbeing located at least partially within said housing, a plurality ofinsulators located between said secondary heat sink and said housing,said insulators serving to form a gap between said secondary heat sinkand said housing, said gap forming an air jacket that at least partiallysurrounds said secondary heat sink, said air jacket being maintained bysaid insulators keeping said housing spaced apart from said secondaryheat sink, said air jacket serving to mitigate against conductance ofheat from said secondary heat sink to said housing, air located in saidair jacket, said air located in said air jacket assisting in heatdissipation by entering said housing through a vent, passing by saidsecondary heat sink in said air jacket and thereby picking up heat fromsaid elongate heat sink, thence exiting said housing to dissipate heat.4. A curing light as recited in claim 3 wherein a material of at leastone of said insulators is selected from the group consisting of rubber,silicone and plastic.
 5. A curing light as recited in claim 3 furthercomprising a fan which tends to draw air from outside said housingthrough a vent on said housing into said air jacket where said air canpick up heat from said secondary heat sink, said fan then moving saidair out of a vent on said housing to the exterior of said housing toachieve heat dissipation.
 6. A light for activating light-activatedmaterials as recited in claim 3 wherein the mass of said secondary heatsink is greater than the mass of said primary heat sink.
 7. A light foractivating light-activated materials comprising: a housing having a top,a bottom, a left side and a right side, a plurality of air vents on saidhousing, a light emission control actuator which when actuated causeslight to be emitted from the light for activating light-activatedmaterials, said light emission control actuator being located on one ofsaid housing left side and said housing right side, a secondary heatsink capable of assisting in heat dissipation, a primary heat sinkattached to said secondary heat sink, said primary heat sink having alongitudinal axis, a mounting platform on said primary heat sink, asemiconductor chip capable of emitting light useful in activatinglight-activated materials materials, said chip being mounted to saidprimary heat sink at said mounting platform, said mounting platformbeing oriented so that light emitted directly in front of said chiptravels at an angle of 30 to 150 degrees with respect to saidlongitudinal axis, at least one insulator located between said secondaryheat sink and said housing, an air jacket formed by a space between saidsecondary heat sink and said housing, said air jacket being maintainedby said insulators keeping said housing spaced apart from said secondaryheat sink, said air jacket serving to avoid conductance of heat to saidhousing, said air located in said air jacket assisting in heatdissipation by entering said housing through a vent, passing by saidsecondary heat sink in said air jacket and thereby picking up heat fromsaid elongate heat sink, thence exiting said housing to dissipate heat afan which tends to draw air from outside said housing through a vent onsaid housing into said air jacket where said air can pick up heat fromsaid secondary heat sink, said fan then moving said air out of a vent onsaid housing to the exterior of said housing to achieve heatdissipation, and a thermoelectric cooler located on said secondary heatsink, said thermoelectric cooler serving to assist in heat dissipation,said fan also serving to move air past said thermoelectric cooler to aidin heat dissipation.
 8. A curing light as recited in claim 7 wherein atleast one of said insulators includes a material that is selected fromthe group consisting of rubber, silicone and plastic.
 9. A light foractivating light-activated materials as recited in claim 7 wherein themass of said secondary heat sink is greater than the mass of saidprimary heat sink.
 10. A light for activating light-activated materialsas recited in claim 7 wherein said chip is selected from the groupconsisting of light emitting diode chips, laser chips, light emittingdiode chip array, diode laser chips, diode laser chip array, surfaceemitting laser chips, edge emitting laser chips, and VCSEL chips.
 11. Alight for activating light-activated materials as recited in claim 7further comprising a dome over said chip.